There are many kinds of guidance systems, which can be roughly divided into six categories according to guidance methods.

① autonomous: this guidance system controls the flight of the aircraft according to the internal or external reference datum of the aircraft. It does not need any artificial control and navigation, nor does it need the cooperation of ground equipment, so it has strong anti-interference ability. The systems applying this method include inertial guidance system and astronomical guidance system.

② beam type: the beam guidance system uses electromagnetic beam guidance, also known as beam steering. The commonly used beams are radio beams and laser beams. The anti-jamming performance is better when guided by laser beam. The guidance accuracy of this guidance method decreases with the increase of distance.

③ command type: the command guidance system sends commands from guidance stations outside the aircraft to control the flight of the aircraft.

④ homing formula: the sensor (seeker) installed on the aircraft senses the energy or sound radiated or scattered by the target and automatically forms guidance instructions to control the flight (see homing guidance system and torpedo acoustic guidance system.

⑤ image matching: the image matching guidance system automatically guides the aircraft to the target by using remote sensing characteristic images.

⑥ compound: the compound guidance system combines the above two methods to give full play to their respective advantages.

according to the nature of the physical quantities used in guidance, guidance systems can be divided into radio guidance, infrared guidance, laser guidance, radar guidance, television guidance and so on.

autonomous guidance system

this kind of system is characterized by complete autonomy, and the guidance signal for controlling the missile's flight is generated by the missile's own guidance equipment, which has nothing to do with the target or command station and is not easily disturbed. This kind of guidance system, because the program is predetermined, is only suitable for attacking fixed targets. It includes:

according to the inertia of the object, measuring the acceleration of the missile to determine the inertial guidance of the missile's flight path;

Terrain matching guidance to guide the missile to fly to the target according to the terrain characteristics;

astronomical guidance based on the relative positions of some stars in space and the earth;

Scheme guidance for controlling missile flight according to pre-installed program.

Remote control guidance system

This kind of system relies on the guidance station to provide guidance signals for missiles, and can also change the flight trajectory at any time according to the movement of the target, which is suitable for attacking moving targets. There are command guidance and beam guidance.

Wired electric instruction guidance

Wired electric instruction guidance, the missile is connected with the command station by wires, and the instructions are transmitted to the missile by wires. The guidance equipment is simple and has strong anti-interference ability. The disadvantage is that it is limited by the length of the conductor, and the action distance is generally within 1 km. After the rise of optical fiber technology, the working distance has increased.

radio command guidance

the most commonly used radio command guidance is radar, which tracks targets and missiles, and the parameters such as position, distance and speed are calculated by computers to form commands and sent to missiles. This kind of guidance method has high guidance accuracy within a certain distance, but its disadvantages are easy to be found by the enemy and poor anti-interference ability.

TV instruction guidance

TV instruction guidance, the target and background images are captured by the camera on the missile and sent to the guidance station, and then the guidance station forms instructions to guide the missile to hit the target. The advantage is that it is clear at a glance, and the most important target can be selected to attack first in the case of multiple targets. The disadvantage is that it is affected by the weather and the action distance is not large.

radar beam guidance

radar beam guidance uses the directional radiation of radar wireless to form a narrow cone-shaped rotating beam in space, which automatically tracks the target, and the missile flies along the beam axis until it hits the target. This guidance method is rarely used now, because it is easily separated from the beam by radio interference.

laser beam guidance

laser beam guidance aims at the target with a laser, and continuously emits laser beams to guide the missile to hit the target. This guidance method is very suitable for anti-tank missiles, but the disadvantage is that the laser can't stop working for a moment, and it is easy to be found and interfered.

homing guidance system

homing means that the missile finds and tracks itself until it finally destroys the target. It usually uses some energy radiated and reflected by the target, such as infrared rays, electromagnetic waves, optical radiation, sound waves and other signals, and relies on the equipment installed on the missile to detect and calculate, forming instructions to make the missile fly to the target. There are active, semi-active and passive types, including:

radar homing guidance. The missile head is equipped with radar, which emits electromagnetic waves to the target and guides the missile to fly according to the target echo.

infrared homing guidance includes an infrared seeker, which uses infrared radiation from the target to convert it into regularly changing electric energy, which is shaped and amplified by electronic circuits to form a guidance signal to guide the missile to the target.

TV homing guidance, there is a TV camera, which uses electron beam scanning to convert the light image of the target and background into electrical signals to guide the missile to track the target.

millimeter wave homing guidance works in the same way as radar homing guidance, but the difference is wavelength. Radar works in microwave band with a wavelength of 1~1 cm, and millimeter wave refers to electromagnetic wave band with a wavelength of 1 ~ 1 mm. It is not affected by the weather and smoke, except by heavy rain, fog, clouds, snow and hail. Millimeter waves can penetrate as well, and it has "limited all-weather ability".